The rates of HIV/AIDS among adolescents are alarming in Sub-Saharan Africa, where sexual transmission is the leading cause of infection with HIV. In Sub-Saharan Africa, the Republic of Botswana has the second highest rate of HIV/AIDS in the world. A limited capacity and infrastructure for rigorous HIV/STD prevention research has hampered efforts to curb the spread of sexually transmitted HIV infection among adolescents in Botswana. Accordingly, the broad long- term objective of the proposed research is to build capacity and infrastructure to develop, implement, and evaluate culturally competent, developmentally appropriate, sustainable interventions suitable for implementation in a variety of settings to dissuade Botswana adolescents from engaging in behaviors that increase their risk for sexually transmitted diseases (STDs), including HIV. This application is a collaborative effort of a multidisciplinary team of researchers at the University of Botswana and the University of Pennsylvania to build such capacity and infrastructure at the University of Botswana. The project will be directed by Professor Bagele Chilsa at the University of Botswana and Professor John Jemmott at the University of Pennsylvania. The capacity building will be organized around three cores. Qualitative and Quantitative Methodology Core, Social and Behavioral Intervention Core, and the Administrative Core. In addition, three research projects that draw upon the cores to address adolescents in different settings are proposed: School-Based HIV/STD Prevention, Church-Based HIV/STD Prevention, and HIV/STD Prevention for Adolescents Living with HIV. The Principal Investigator of each core and research project will be a University of Botswana faculty member and the Co-Principal Investigator will be a University of Pennsylvania faculty member. This partnership is committed to developing a creative comprehensive and interdisciplinary HIV/STD prevention research program on adolescents that is fully integrated within the research and education mission of the University Botswana and dedicated to addressing the urgent need to stem the devastating impact of HIV on one of the highest risk adolescent populations in the world.